N = int(input())

if N >= 30:
    print("Yes")
else:
    print("No") N = int(input()) N int(input()) int input() input if N >= 30:
    print("Yes")
else:
    print("No") N >= 30 N 30 print("Yes") print "Yes" print("No") print "No" N = int(input()) int(input()) N
N = int(input())

if N >= 30:
    print("Yes")
else:
    print("No")